Laboratory Manual for General Biology I
(BSC 1010C)
Lake-Sumter State College
Science Department
Leesburg
Table of Contents
Note to Students ........................................................................................................................................... 3
Exercise 1 - Measurements and Lab Techniques .......................................................................................... 4
Exercise 2 - Functional Groups, Organic Molecules, Buffers, and Dilutions ............................................... 13
Exercise 3 - Qualitative Analysis of Biological Molecules ........................................................................... 23
Exercise 4 - The Microscope ....................................................................................................................... 31
Exercise 5 - Cell Structure and Membrane Function .................................................................................. 46
Exercise 6 - Enzyme Activity ........................................................................................................................ 56
Exercise 7 - Respiration ............................................................................................................................... 63
Exercise 8 - Photosynthesis ......................................................................................................................... 67
Exercise 9 - Cell Division .............................................................................................................................. 73
Exercise 10 - DNA Fingerprinting ................................................................................................................ 81
Exercise 11 - Genetics ................................................................................................................................. 96
A significant portion of this lab manual is used with the kind permission of the Science Department at
Seminole State College, Sanford, Florida.
Lake-Sumter State College, Leesburg Laboratory Manual for BSC 1010C
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Note to Students
Students should read and study the exercises before coming to the laboratory and should supply
themselves with the necessary materials including the text book, lecture notes, laboratory manual,
calculators, pens, and pencils. All students are required to wear appropriate clothing to lab as outlined
by the lab instructor as well as follow all safety precautions during laboratory exercises.
Lake-Sumter State College, Leesburg Laboratory Manual for BSC 1010C
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Exercise 1 - Measurements and Lab Techniques
Introduction
In scientific experiments, observation and accurate measurements are essential. The investigations in
this exercise will familiarize you with some of the methodologies and equipment in use in biology
laboratories.
Your objective is to learn to correctly select and use equipment to obtain accurate results, while
avoiding damage to the equipment or yourself.
Materials
Equipment
meter sticks
metric rulers
blocks of various sizes
irregularly shaped objects (fossils, rocks, bones, etc.)
500 ml graduated cylinders
triple beam balances
Part A: The Metric System
Scientific measurements are expressed in the units of the metric system or its modern day successor,
the International System of Units (SI). We will use this system exclusively throughout this course.
The metric system was invented by the French vicar Gabriel Moutin in 1670 and officially adopted as the
standard for weights and measures in France in 1795. Since then it has spread throughout much of the
rest of the world. Although the United States traditionally uses the English system, its use has become
more common in recent years. You may have even noticed canned goods and drinks in grocery stores
are given in metric as well as English units.
Just like in the English system, the metric system has three categories of units. For distance, it is meter,
for volume, liter, and for mass, gram. The metric system makes use of prefixes to change the value of
the unit in multiples of 10 (Table 1.1)
Lake-Sumter State College, Leesburg Laboratory Manual for BSC 1010C 4
Exercise 1 – Measurements and Lab Techniques
Table 1.1. Metric System Units
Exponential multiplier
Length
Volume
Mass
103
kilometer (km)
kiloliter (kl)
kilogram (kg)
102
hectometer (hm)
hectoliter (hl)
hectogram (hg)
101
decameter (dam)
decaliter (dal)
decagram (dag)
100 = 1
meter (m)
liter (l)
gram (g)
-1
10
decimeter (dm)
deciliter (dl)
decigram (dg)
10-2
centimeter (cm)
centiliter (cl)
centigram (cg)
-3
10
millimeter (mm)
milliliter (ml)
milligram (mg)
10-4
These units have no prefixes
10-5
10-6
micron (μ)
microliter (μl)
microgram (μg)
-7
10
These units have no prefixes
10-8
10-9
nanometer (nm)
nanoliter (nl)
nanogram (ng)
Use this mnemonic device to remember the order of the prefixes:
kids have dropped over dead converting many blank blank metric blank blank numbers
Conversion between related units is accomplished by moving the decimal point the appropriate number
of places left or right (Fig. 1.1).
Fig. 1.1 Metric Unit Conversion Staircase
kilo (k)
hecto (h)
deca (dam)
m, l, g
deci (d)
centi (c)
milli (m)
micron (μ)
nano (n)
Move “up” the staircase to larger units, “down” to smaller ones. As example, to convert 37.35
decimeters (dm) to millimeters (mm), move the decimal point 2 places to the right (3735).
Lake-Sumter State College, Leesburg Laboratory Manual for BSC 1010C
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Exercise 1 – Measurements and Lab Techniques
Fill in the basic metric unit for each measurement in Table 1.2
Table 1.2 Basic Metric Units
Measurement
Length
Volume
Mass
Basic Metric Unit
Carry out the metric conversions in Table 1.3.
Table 1.3 Practice Metric Conversions
550 ml
3.7 g
20 km
78.4 cm
212 μl
67.5 dam
500 μm
__________ l
__________ mg
__________ m
__________ mm
__________ ml
__________ μm
__________ mm
Part B: Length Measurements
Length measurements are made with a metric ruler. When using a linear device, you should extend
your answer at least to the finest divisions on the device. For example, if you have a meter stick with
markings to the millimeter, you could measure your height to the nearest millimeter (e.g., 1754
millimeters or 1.754 meters). The size of objects falling between marked divisions may be interpolated.
Interpolation is an estimation how the distance an object extends between the smallest marks on the
device.
Part B1: Metric Height
Procedure
1. Obtain a meter stick
2. Find a partner and stand them with their back against a wall or door frame
3. Make a small mark at the level of the top of their head
4. Measure this height in centimeters making the most accurate measurement you can with the
meter stick
5. Repeat the procedure with yourself and record your height here __________ cm
Part B2: Calculating Surface Area to Volume Ratios (SA : Vol)
w
h
l
Procedure
1. Use the dimensions given in table 1.4 for various block sizes, calculate total surface area and
volume and enter in Tables 1.5 and 1.6
Lake-Sumter State College, Leesburg Laboratory Manual for BSC 1010C
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Exercise 1 – Measurements and Lab Techniques
Table 1.4 Block Dimensions
l (cm)
w (cm)
h (cm)
Small
Medium
Large
Calculating Surface Area:
Surface area of a rectangular block = 2 (l x w) + 2 (l x h) + 2 (w x h).
Use the data in Table 1.4 to fill in Table 1.5.
Table 1.5 Surface Area Calculations
Small
Medium
calculations
calculations
SA __________ cm2
SA = __________ cm2
Large
calculations
SA = __________ cm2
Calculating Volume:
Volume of a rectangular block = l x w x h
Fill in Table 1.6
Table 1.6 Volume Calculations
Small
calculations
Vol __________ cm3
Medium
calculations
Vol __________ cm3
Lake-Sumter State College, Leesburg Laboratory Manual for BSC 1010C
Large
calculations
Vol __________ cm3
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Exercise 1 – Measurements and Lab Techniques
Calculating Surface Area : Volume (SA : Vol)
Divide the surface area (cm2) by the volume (cm3) recording your answer in Table 1.7
Table 1.7 Surface Area, Volume, and SA: Vol
Surface area (cm2)
Small
Medium
Large
Volume (cm3)
SA : Vol
Use the data from Table 1.7 to construct a bar plot in Fig. 1.2.
Fig. 1.2 Relationship Between SA : Vol and Block Size
The plot just constructed provides a visual illustration of the changes in SA : Vol with blocks of different
volumes.
Describe the kind of relationship you see:
This SA : Vol ratio is very important in biology and helps to explain why cells have typically not grown
larger than microscope size. The SA : Vol affects the movement of materials in and out of cells. Very
small cells have high ratios and can usually supply most all the cell’s transportation requirements
through diffusion. But, as you noticed in this procedure an object’s ratio decreases relatively quickly as
it grows in size. This larger size means less surface area is available per unit of volume. The result is as
cells grow larger, diffusion is not longer sufficient to meet all the cells needs. Cells must either divide to
maintain that larger ratio or develop elaborate internal transport mechanisms. These topics will be
discussed further in later sections of this course.
Lake-Sumter State College, Leesburg Laboratory Manual for BSC 1010C
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Exercise 1 – Measurements and Lab Techniques
Part C: Measuring Volume of Irregular Shaped Solids
Calculation of the volume of regularly shaped objects like rectangular blocks or spheres is
straightforward. However, how can we obtain the volume of something like a piece of bone, or rock, or
a fossil? Their irregular shapes preclude the use of any formula. However, two important facts are
useful to remember
o A submerged object will displace an amount of water equal to its volume
o 1 ml = 1 cm3
Procedure
1. Obtain a 500 ml graduated cylinder
2. Fill cylinder to about the midway mark with tap water
3. Note the level of water in the cylinder in ml
Reading a graduated cylinder
Graduated cylinders are marked off in volume units
Larger units are indicated (e.g., 10 ml, 20 ml, 50 ml, etc.)
Smaller units are not marked but are indicated
You must pay attention to these smaller, unmarked units to get an accurate
reading for volume
Due to capillary attraction, a liquid in a graduated cylinder will not form a flat surface.
Instead, it curves up the sides forming a dip or meniscus. By convention, we always
read the volume of the liquid from the bottom of the meniscus (Fig. 1.3)
Fig. 1.3 Graduated cylinder readings (record you readings in the blanks)
___ ml
___ ml
___ ml
4. Being careful not to splash out any of the water in the cylinder, submerge the irregularly shaped
object. Make sure it is completely underwater. Objects that float should be held underwater
5. Make note of the level of water in the graduated cylinder again
6. Subtract the initial volume of water from this final reading (express your answer in cm3)
7. Record your data in Table 1.8
Table 1.8 Water Displacement Data
Irregularly shaped object
Lake-Sumter State College, Leesburg Laboratory Manual for BSC 1010C
Volume (cm3)
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Exercise 1 – Measurements and Lab Techniques
Part D: Measuring Mass and Density
Procedure
1. Use a triple-beam balance to determine the mass (in grams) of the objects listed in Table 1.9
2. Calculate the volume of these objects using the methods described previously
3. Calculate density of each object
Density = mass (g) / volume (ml or cm3)
4. Record your answers in Table 1.9
Table 1.9 Mass, Volume, and Density of Various Objects
Mass (g)
Volume
(cm3 or ml)
Density
(g / cm3 or ml)
irregularly shaped object _______________________
small block (volume from Table 1.7)
medium block (volume from Table 1.7)
The density of water is 1 g /ml or cm3.
In comparing the densities of the objects in Table 1.9 to the density of water,
which objects float?
The densities of these objects are __________ than that of water.
which objects sink?
The densities of these objects are __________ than that of water.
Lake-Sumter State College, Leesburg Laboratory Manual for BSC 1010C
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Exercise 1 – Measurements and Lab Techniques
Practice Problems
1. Calculate the surface area and volume of a rectangular solid measuring 8.6 cm in length, 2.4 cm
in width, and 3.8 cm in height (use appropriate units). The mass of this block is 121.6 g. What is
its density and will it sink or float in water?
2. Calculate the surface area and volume of a rectangular solid measuring 43 mm in length, 12 mm
in width, and 19 mm in height (report your answer in cm2 and cm3). The mass of this block is
8.5 g. What is its density and will it sink or float in water?
Lake-Sumter State College, Leesburg Laboratory Manual for BSC 1010C
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Exercise 1 – Measurements and Lab Techniques
3. Initial volume of water in a graduated cylinder is 0.26 l. Completely submersing an irregularly
shaped object into the water raises the water level to 512 ml. What is the volume of the object
(express your answer in cm3)? The mass of this object is 60 g. What is its density and will it sink
or float in water?
4. A principle of ecology known as Bergmann’s rule states an organism of a given species will be
larger in colder latitudes than those in warmer ones. For example, grey squirrels (Sciurus
carolinensis) in Florida are significantly smaller than their counterparts in New York. Using what
you have learned about changes in surface area with volume and its implications for membrane
transfer, provide a scientifically reasonable explanation for this observation.
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